Feature: 1.Reusable Washable Filter: Changing your paper filter cartridge is part of your routine maintenance for your pool and regular replacement of the cartridge can prove costly. These washable and re-usable foam filters will reduce your costs. 2.Long Working Time: Initial cost of this cartridge is slightly more than a paper cartridge yet will outlast a cartridge by a long way. 3.Durable: This Foam filter will outlast your paper cartridges and can be washed and re-used several times over. 4.Reusable Washable: Advises changing a paper cartridge each week, whereas these foams can simply be washed and put back. 5.Keep Water Clean: It will be a great water cleaner for swimming pool. Specifications: Material: Sponge Color: blue Size: L 20*10*4cm M 10.2*9.3*3cm S 10.8*7.3*4cm Package Contents: 1 * Filter Sponge Notes: 1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you 2. Please allow 0.1-2cm measuring deviation due to manual measurement.